SSIS And Load Date

I have an SSIS package that imports data. It's working fine except I've been told that the Load_Date field needs to have the same date for each record in the table (the table gets truncated and then loaded each time the SSIS package runs). I created the table with a default of getdate() for Load_Date but I've been told not to do it that way and to have a variable in SSIS to populate Load_Date to make sure it's the same for every record. I've set up a variable in SSIS. I made it a datetime type of variable. It defaults the value to the current date (at that time) but doesn't let me change it to getdate(). I think the way to use the variable is to have a derived columns step that uses the variable Load_Date and then in mappings, set the column equal to the variable. But how do I set the variable equal to getdate() so it can be used for each row?

Thanks